By Jim McCausland, Sunset Magazine

When you first plant a tree or shrub, it takes the plant awhile to send roots deep and wide enough to live on ordinary garden watering. During that period, you need to irrigate right over the root zone, and water slowly enough to penetrate deeply.

Most of us encircle the trunk with earthen watering wells to do the job, but last weekend a landscape designer showed me the device she uses to accomplish the same thing—but with no danger of washouts. 

Called a Tree Gator, it looks something like a leaky life vest filled with water. There are two versions: a 20-gallon vertical one, and a 15-gallon horizontal. You put them around the trunks, fill them with water, and they spend the next several hours watering for you. A few days later, you refill them and they go through their drip irrigation routine again.

The 20-gallon version can wrap around a 4-inch trunk, so it needs 25 inches clearance between the ground and the lowest branch. The 15-gallon version can handle a 6-inch diameter trunk, but it lies on the ground, so it can easily work under shrubs or low-branched spreading trees.

You can buy these at TreeGator.com for less than $25 each—and no, I have no connection with the manufacturer for this, no free samples, nothing. It just seems like a useful product.